With the Sony NWWS413 MP3 player, you can enjoy your music while running, cycling, or swimming. The MP3 player has a storage capacity of 4GB and works in extreme circumstances: in salty seawater, on a sandy beach, in a pool containing chlorine, on dusty trails, and at temperatures of -5 to 45°C. Thanks to the integrated earbuds, you won't have the hassle of cables getting in the way, and you won't need to establish a Bluetooth connection to your smartphone. Use the USB port to transfer your music and charge the device. A fully charged battery will provide 12 hours of listening enjoyment. Gotta run? Give it a quick 3-minute charge for one hour of playback.